1. Field of the Invention
The present invention relates generally to electrical panel meters, and more specifically, to a system and method for utilizing test pulses in electrical panel meters to enable their use for revenue metering.
2. Discussion of the Related Prior Art
Electric utility companies use revenue meters to track electric usage by customers. These meters track the amount of power consumed at a particular location. These locations range from commercial businesses to residential homes. The electric utility companies use the revenue meter to charge its customers for their power consumption, i.e., revenue metering. Typically, the revenue meter connects between utility power lines supplying electricity and a usage point, namely a residence or commercial place of business.
Traditionally, panel mounted or panel meters were utilized only for a visual indication of instantaneous readings on an electrical switchboard panel. In the past, these panel meters were exclusively analog, and were utilized for measuring the amount of voltage, current, wattage etc., supplied to consumers through the utility lines. As metering technology progressed, the panel meters became multifunction, and have the ability to measure energy as well as instantaneous measurements.
However, even though the panel meters had the ability to measure energy, the panel meters did not have the ability to be tested and verified for accuracy using traditional Utility energy based testing methods. Furthermore, since these types of meters are used generally for indication, the hardware design for panel meters was limited to a low accuracy standard, e.g., 1%, making energy test pulses futile. Therefore, conventional panel meters do not have the capability to be used for revenue billing measurements.
Traditionally, revenue meters used mechanical or analog means to track the amount of consumed power. The inductive spinning disk power meter is still commonly used. The spinning disk drives mechanical counters that track the power consumption information. Newer to the market are electronic power meters, which have replaced the older mechanical meters. Electronic revenue meters utilize digital sampling of the voltage and current waveforms to generate power consumption information. In addition to monitoring power consumption, electronic revenue meters can also monitor and calculate power quality, e.g., voltage, current, real power, reactive power, apparent power, etc. These power quality measurements and calculations are displayed on an output display device on the meter.
The traditional method for testing the revenue meters is to take an infrared pulse supplied by the mechanical energy meter, which pulses proportionally to the energy accumulated, e.g., one revolution of the inductive spinning disk equals one pulse. The standard revolution value is 1.8 watt-hours per pulse, but this value is generally adjustable. The pulses are then counted and compared to pulses generated by a standard energy reference. If the accuracy of the taken infrared pulses is within the percentage required by the industry standards, then the energy meter would be determined to be in good standing and put into service. Otherwise, the meter would be re-calibrated and tested again or not used.
The veracity of panel measuring devices could not be determined in the field through the use of traditional methods and equipment. Since utility testing equipment relies on energy pulse accumulation of which are not available with indication panel instrumentation. Therefore, these meters would not be used for billing purposes as the supplied data can potentially be erroneous.